Optical switch and optical waveguide device

ABSTRACT

An optical switch allowing easy alignment of a cut portion with a pressurizing member pressurizing a waveguide accommodating sheet, an optical waveguide device, are obtained. The optical switch includes a cut portion formed by cutting in the waveguide accommodating sheet from one surface thereof, a contact member at least on that side of the waveguide accommodating sheet which is opposite to the cutting side, having a fixed portion fixed in the vicinity of the cut portion and a pressurizing portion positioned to be continuous with the fixed portion and two-dimensionally overlap the cut portion, and a piezoelectric actuator positioned such that the pressurizing portion is sandwiched between the actuator and the waveguide accommodating sheet, thereby moving to press the pressurizing portion against the waveguide accommodating sheet and to disengage the pressurizing portion from the waveguide accommodating sheet.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an optical switch for use inswitching connection destinations in optical communication facilities inoptical communication and an optical waveguide device.

[0003] 2. Description of the Background Art

[0004] Referring to FIG. 10, a conventional optical switch is providedfor an optical waveguide 105 in film-like polymer 102 as a waveguideaccommodating sheet pressed by a press plate 103. A polyimide film orthe like may be used as film-like polymer forming a waveguideaccommodating sheet. As shown in FIG. 11, in an optical connectionon-state (referred to as on-state hereinafter) in which a drivemechanism (push rod) 106 does not press a cut portion at theintersection of the waveguides running vertically and horizontally,waveguide accommodating sheet 102 has cut end surfaces 102 a tightlyconnected at the cut portion. Therefore, a core, which is waveguide 105,is also tightly connected at the cut portion. As a result, lightarriving at the tightly connected cut portion passes through the cutportion uninterruptedly.

[0005] On the other hand, in an optical connection off-state (referredto as off-state hereinafter) in which push rod 106 presses the cutportion, as shown in FIG. 12, push rod 106 forces end surfaces 102 aapart from each other to bring them in contact with air. Therefore,light propagating in a waveguide with a high index of reflection istotally reflected by an air layer of gap 109 to change the directionapproximately 90° for propagation.

[0006] With the mechanism described above, in FIG. 10, in the opticalconnection on-state at the intersection of waveguides, optical inputsL1, L2 pass uninterruptedly through the part where cut end surfaces 102a are tightly connected at intersection 111 of waveguides. On the otherhand, in the optical connection off-state at the intersection ofwaveguides, both light inputs L1 and L2 are totally reflected at theoptical switch part to change the direction approximately 90° forpropagation in a prescribed direction. As described above, theconventional optical switch is characterized in that push/pull of onepush rod 106 switches the direction of light.

[0007] The optical switch described above causes a problem when theoff-state changes to the on-state. Specifically, when the off-state inwhich light is totally reflected by pushing of the push rod changes tothe on-state in which light is transmitted, only a restoring force isexerted which results from the elastic force of the film-like polymerwhen the push road retracts. Therefore, cut end faces 102 a of film-likepolymer 102 are not connected tightly enough, and core 105 forming thewaveguide is thus not connected tightly enough.

[0008] Unfortunately, in the configuration of the optical switch shownin FIGS. 11 and 12, it is difficult to arrange the push rods accuratelyin alignment with the same number of myriad cut portions. In opticalswitches where thirty-two vertical waveguides cross over thirty-twohorizontal waveguides to form a matrix with thirty-two rows andthirty-two columns, all of the 1024 piezoelectric actuators must be inalignment with the cut portions within a given accuracy. A large numberof steps are required to effect alignment of such an enormous amount ofpiezoelectric actuators individually for each piezoelectric actuator,and in addition a high degree of skill is required to attain theintended accuracy of arrangement.

SUMMARY OF THE INVENTION

[0009] An object of the present invention is to provide an opticalswitch allowing easy alignment of a film-like polymer pressurizingmember with a cut portion and easy tight connection of cut end faces 102a, an optical waveguide device.

[0010] An optical switch in accordance with the present invention isprovided in an optical waveguide device including a waveguide allowingpropagation of light and a waveguide accommodating sheet accommodatingthe waveguide. The optical switch includes: a cut portion formed bycutting in the waveguide accommodating sheet from one surface thereofacross the waveguide; a contact member positioned at least on that sideof the waveguide accommodating sheet which is opposite to a side of thecutting in and having a fixed portion and a pressurizing portion, thefixed portion being fixed in the vicinity of the cut portion, thepressurizing portion being positioned to be continuous with the fixedportion and two-dimensionally overlap the cut portion; and a drivemember positioned such that the pressurizing portion is sandwichedbetween the drive member and the waveguide accommodating sheet wherebythe drive member advances toward the pressurizing portion to press thepressurizing portion against the waveguide accommodating sheet andretracts away from the pressurizing portion to disengage thepressurizing portion from the waveguide accommodating sheet.

[0011] Because of this configuration, it becomes unnecessary to alignthe drive member with the cut portion of the waveguide accommodatingsheet accurately. More specifically, since gap creation or connection inthe cut portion is effected by abutment or disengagement of thepressurizing portion moved by the drive member, it is possible todecrease the accuracy of alignment of the drive member with the cut.

[0012] Note that the cutting-in at the cut portion may have any depth aslong as it traverses the waveguide. For example, the cut may extendthrough the entire thickness of the waveguide accommodating sheet, thatis, the sheet may be completely cut off. In case of this cut-off, “atleast on that side of the waveguide accommodating sheet which isopposite to a side of the cutting in” described above should read as “atleast one surface of the waveguide accommodating sheet”.

[0013] The pressurizing portion may include a sheet contact portion tocome into contact with the waveguide accommodating sheet at the cutportion and a drive member contact portion to come into contact with thedrive member. The sheet contact portion and the drive member contactportion may be arranged to be two-dimensionally separated.

[0014] When the drive member contact portion and the sheet contactportion are located near and far from the fixed portion, respectively, asmall stroke of the drive member can provide the sheet contact portionwith a large stroke. Therefore, when the drive member is formed, forexample, with a piezoelectric actuator, a piezoelectric actuator havinga small amount of displacement can be used, so that the piezoelectricactuator and the electric system operating thereof can be reduced insize.

[0015] The contact members positioned corresponding to the plurality ofcut portions in the optical waveguide device may be formed from onemetal plate that is integrally formed.

[0016] Because of this configuration, an optical waveguide device havingbetter control of transmitting light can be obtained with a highproduction yield.

[0017] It becomes unnecessary to arrange the pressurizing portion andthe fixed potion for each optical switch, and only the one metal plateintegrally formed is simply aligned with the waveguide accommodatingsheet. Therefore, it becomes easy to align the pressurizing portion withthe cut portion.

[0018] In the waveguide accommodating sheet, a frame portion may beprovided along a peripheral portion of the waveguide accommodatingsheet, and the integrally formed metal plate may be arranged such thatit is surrounded by the frame portion.

[0019] By fitting the integrally formed metal plate into the frameportion, for example, in an extreme case, it may be unnecessary to alignthe cut portion with the pressurizing portion in the metal plate.

[0020] The optical waveguide device described above may include a casingsupporting the waveguide accommodating sheet and the drive member. Thecasing may have approximately the same thermal expansion coefficient asthe drive member.

[0021] The waveguide accommodating sheet can be pressurized with acertain amount of displacement, independent of the environmenttemperature.

[0022] In an optical waveguide device in accordance with the presentinvention, each optical switch includes a cut portion formed by cuttingin the waveguide accommodating sheet from one surface thereof across thewaveguide, and a contact member positioned at least on that side of thewaveguide accommodating sheet which is opposite to a side of the cuttingin and having a fixed portion and a pressurizing portion. The fixedportion is fixed in the vicinity of the cut portion and the pressurizingportion is positioned to be continuous with the fixed portion andtwo-dimensionally overlap the cut portion. The optical switch furtherincludes a drive member positioned such that the pressurizing portion issandwiched between the drive member and the waveguide accommodatingsheet, whereby the drive member advances toward the pressurizing portionto push the pressurizing portion against the waveguide accommodatingsheet and retracts away from the pressurizing portion to disengage thepressurizing portion from the waveguide accommodating sheet.

[0023] The optical waveguide device may include an electrical drive unitelectrically driving the drive member. The electrical drive unit may beformed by stacking a plurality of circuit boards, and adjacent drivemembers among the drive members may be connected to different circuitboards.

[0024] The electrical drive unit driving the drive member can be reducedin size without causing a short circuit, and in addition the opticalwaveguide device can be reduced in size.

[0025] The foregoing and other objects, features, aspects and advantagesof the present invention will become more apparent from the followingdetailed description of the present invention when taken in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026]FIG. 1 is a cross sectional view of an optical switch in anoptical connection on state in accordance with a first embodiment of thepresent invention.

[0027]FIG. 2 is a cross sectional view of the optical switch in anoptical connection off state in accordance with the first embodiment ofthe present invention.

[0028]FIG. 3 shows fixed portions in a grid pattern and leaf springs aspressurizing portions, formed by integrally forming a metal plate, in anoptical waveguide device including a plurality of optical switches ofthe first embodiment of the present invention.

[0029]FIG. 4 is a cross section of FIG. 3 taken along IV-IV.

[0030]FIG. 5 is a cross sectional view of the optical switch in theoptical connection off state in accordance with a second embodiment ofthe present invention.

[0031]FIG. 6 is a cross sectional view showing the optical waveguidedevice in accordance with a third embodiment of the present invention.

[0032]FIG. 7 is a cross sectional view showing the optical waveguidedevice in accordance with a fourth embodiment of the present invention.

[0033]FIG. 8 is a cross sectional view showing an example of an opticalswitch in the optical connection on state.

[0034]FIG. 9 is a cross sectional view showing the optical switch in theoptical connection off state.

[0035]FIG. 10 is a perspective view of the optical waveguide devicehaving a conventional optical switch arranged.

[0036]FIG. 11 is a cross sectional view showing the conventional opticalswitch in the optical connection on state.

[0037]FIG. 12 is a cross sectional view showing the conventional opticalswitch in the optical connection off state.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0038] Embodiments of the present invention will now be described withreference to the figures.

[0039] An invention was made by the inventor common to the presentapplication, in which a highly reliable optical switch is providedallowing for stable and high accurate optical connection on/offoperations at the waveguide intersection. An example of this opticalswitch is shown in FIGS. 8 and 9. In the optical switch shown in FIGS. 8and 9, push rods 106 a and 106 b including piezoelectric actuators arearranged at both the upper and lower sides of cut portion 102 a of thefilm-like polymer. These push rods 106 a and 106 b are supported by pushrod-supporting plate 116 a and 116 b, respectively.

[0040] As shown in FIG. 8, in order to create the on-state, voltage isapplied to the piezoelectric actuator arranged on the opening side ofthe cut portion, that is, on the upper side so that push rod 106 bpressurizes the cut portion. This pressurization deforms film-likepolymer 102 in a concave manner, causing the cut end faces to connectwith each other, thereby realizing the on-state.

[0041] On the other hand, in order to create the off-state, voltage isapplied to the piezoelectric actuator arranged on the side opposite tothe opening side of the cut portion so that the push rod pressurizes thefilm-like polymer. This pressurization disconnects the cut surfaces fromeach other to create a gap 109, thereby realizing the off-state. Theoptical switch described above enables to achieve the reliable contactof cut end faces, while even with this optical switch it is difficult toarrange the push rods accurately in alignment with the same number ofmyriad cut portions. The following embodiments of the present inventionhave all solved this problem.

[0042] (First Embodiment)

[0043]FIGS. 1 and 2 show an optical switch in a first embodiment of thepresent invention in cross section. Fixed portions 4 b and 3 b are fixedby adhesive respectively on the upper and lower surfaces of a waveguideaccommodating sheet. Pressurizing portion 3 a, 4 a is arranged such thatit is continuous with the fixed portion and kept away from waveguideaccommodating sheet 1. Pressurizing portion 3 a, 4 a is provided withsheet-side protruding portion 13 a, 14 a which comes into contact withwaveguide accommodating sheet 1 and drive member-side protruding portion13 b, 14 b which comes into contact with a drive member.

[0044] A waveguide 2 is accommodated in waveguide accommodating sheet

[0045] 1. A cut portion 7 extends to such a depth as to at leasttraverse waveguide

[0046] 2. As long as cut surfaces 7 a and 7 b are in contact with eachother in the on-state, the cut of the waveguide accommodating sheet mayinclude one in which the entire thickness is completely cut off. InFIGS. 1 and 2, the drive member is formed with a piezoelectric actuator5 a, 5 b. At the base portion of piezoelectric actuator 5 a, 5 b, anactuator supporting plate 6 a, 6 b including a circuit board foroperating the piezoelectric actuators is arranged.

[0047] The operation of the optical switch will now be described. InFIG. 1, in which the optical switch is in the on-state and light passesthrough the optical switch linearly, cut surfaces 7 a and 7 b at cutportion 7 are tightly connected. In order to realize such tightconnection, a sheet-side protrusion 14 a of pressurizing portion 4 athat is positioned on the cut side (the upper side) pressurizes thewaveguide accommodating sheet, while a sheet-side protrusion 13 a ofpressurizing portion 3 a on the lower side is kept away from thewaveguide accommodating sheet. Pressurization by pressurizing portion 4a forces the waveguide therearound including cut portion 7 to be concaveon the upper side and convex on the lower side.

[0048] On the other hand, in FIG. 2 in which cut portion 7 has its gapincreased and cut surfaces 7 a and 7 b are kept apart from each other,pressurizing portion 3 a on the side opposite to the cut side (the lowerside) pushes up the waveguide accommodating sheet from the lower side toopen the cut portion. Actuator 5 b on the upper side is recessed andpressurizing portion 4 a on the upper side is kept away from thewaveguide accommodating sheet. Pressurization as described above deformsthe waveguide accommodating sheet to be concave on the lower side andconvex on the upper side, as shown in FIG. 2.

[0049]FIG. 3 shows a metal plate including the fixed portion and thepressurizing portion of the optical switch in FIG. 1, integrally formedfor use in the optical waveguide device. In FIG. 3, fixed portion 3 b, 4b formed in a grid pattern forms a frame of metal plate for each opticalswitch. This frame is arranged such that it surrounds the cut portion ofthe waveguide accommodating sheet. Leaf spring 3 a, 4 a as apressurizing portion is provided corresponding to the cut portion suchthat it protrudes from the frame. The thickness of fixed portions 3 b, 4b formed in a grid pattern is formed to be greater than the thickness ofthis leaf spring. The pressurizing portion except for the base portionthereof is kept apart from the frame since it needs to swing accordingto contact and non-contact with the drive member. This leaf spring ispushed by the actuator as a drive member so that it elastically deformsto come into contact with the waveguide accommodating sheet and restoresto the original shape by elastic force when the drive member is away.

[0050] An alignment marker 19 is provided on the corner where thevertical bar and the horizontal bar of the frame cross each other.

[0051]FIG. 4 is a cross section of FIG. 3 taken along IV-IV. As shown inFIG. 4, the leaf spring as a pressurizing portion is provided with adrive member-side protrusion 13 b, 14 b on the frond surface side nearthe frame and with a sheet-side protrusion 13 a, 14 a on the end sidefar from the frame.

[0052] Leaf springs 3 a, 4 a as pressurizing portions and fixed portions3 b, 4 b in a grid pattern are formed in the metal plate that isintegrally formed. Alternatively, the pressurizing portion and the fixedportion in a grid pattern may be separately formed and then connected.When the thickness of the fixed portion is greater than that of the leafspring, in many cases, it may be simpler to fabricate separately andthereafter connect them by affixing and the like.

[0053] The aforementioned metal plate is affixed onto either side of apolyimide film as a waveguide accommodating sheet. In this affixation,where marker 19 for position adjustment provided on the metal plate isused as a reference for alignment with the cut portion of the polyimidefilm.

[0054] In the optical switch of the present embodiment, thepiezoelectric actuator acts with the cut portion with the leaf springinterposed. Therefore, even if the piezoelectric actuator is arrangedoffset from the cut portion to a degree, the cut portion can be openedor tightly connected by means of the leaf spring.

[0055] Desirably, metal having a thermal expansion coefficientequivalent to that of polyimide film, about 50 ppm is used for a metalplate forming leaf spring 3 a, 4 a. For example, stainless steel has athermal expansion coefficient of about 20 ppm and therefore stainlesssteel plate is desirably used as the metal plate. In such a manner, theuse of the metal plate having a thermal expansion coefficient equivalentto that of the polyimide film can prevent the stress inwardly of thepolyimide film.

[0056] In addition, provision of protrusion 13 a, 14 a, 12 b, 14 b onthe front and back faces of the leaf spring can further ensure theaction of the piezoelectric actuator onto the cut portion.

[0057] (Second Embodiment)

[0058]FIG. 5 is a cross sectional view of the optical switch in a secondembodiment of the present invention. Drive member-side protrudingportion 14 a of the leaf spring in the optical switch is positioned tobe more proximate to fixed portion 3 b than in the first embodiment.

[0059] Therefore, when the reciprocating stroke for sheet-sideprotruding portion 13 a to separate or tightly connect cut surfaces 7 aand 7 b is the same as in the first embodiment, the reciprocating strokeof the piezoelectric actuator can be made smaller. Here, the load neededfor the piezoelectric actuator to push the drive member-side protrudingportion increases in inverse proportion to the distance from the baseportion of the leaf spring as a fulcrum to each protruding portion,according to the principle of leverage. This, however, does not pose asignificant problem since the load needed to deform the polyimide filmis originally small.

[0060] With the configuration described above, it is possible to set theamount of displacement of the piezoelectric actuator at a small value.Therefore, it is possible to use a piezoelectric actuator with a smallamount of displacement and thus to reduce the size of the optical switchand optical waveguide device. In addition, it is possible to increasethe speed of on/off operation of the optical switch.

[0061] (Third Embodiment)

[0062]FIG. 6 is a cross sectional view of the optical waveguide deviceof a third embodiment of the present invention. In the waveguideaccommodating sheet of the optical waveguide device, a silicon substrateused in the manufacturing process is etched and a substrate frame 21 isleft along the peripheral portion of the waveguide accommodating sheet.A fiber coupling groove 24 is formed within substrate frame 1 toaccommodate an end portion of an optical fiber which is coupled to thewaveguide within the polyimide film. The end portion of the opticalfiber is inserted into fiber coupling groove 24. As a result, couplingof optical fiber 22 with waveguide 2 is realized.

[0063] Substrate 21 can be used as a reference frame for affixing themetal plate including the leaf spring to the polyimide film. Morespecifically, the metal plate is brought to be surrounded by substrateframe 21, and the metal plate can be arranged on the polyimide filmaccurately using marker 19 as a reference.

[0064] A mirror frame 23 is arranged as a member which supports fibercoupling groove 24 and piezoelectric actuators 5 a and 5 b. In thismirror frame 23, optical fiber 22 is pulled from the outside andaccommodated in fiber coupling groove 24. Furthermore, a lower substrate6 a and an upper substrate 6 b that fix piezoelectric actuators 5 a and5 b, respectively, are supported at its edge part by mirror plate 23.

[0065] In accordance with the present embodiment, substrate frame 21formed of the patterned silicon substrate is used as a frame for fixingthe polyimide film and upper and lower substrates 6 a and 6 b, so thatthe metal plate, the optical fiber and the piezoelectric actuator can befixed more easily.

[0066] Since mirror frame 23 serves to determine the distance (height)between polyimide film 1 and piezoelectric actuator 5 a, 5 b, it isdesired that mirror frame 23 has a thermal expansion coefficientequivalent to that of the piezoelectric actuator. By adjusting thermalexpansion coefficient in this way, even if the length of thepiezoelectric actuator changes due to environment temperaturevariations, mirror frame 23 can also have its size changed similarly.Therefore, the space between polyimide film 1 and the end point ofpiezoelectric actuator 5 a, 5 b is not changed, so that the polyimidefilm can be pressurized with a prescribed constant amount ofdisplacement of the piezoelectric actuator.

[0067] (Fourth Embodiment)

[0068]FIG. 7 is a diagram showing the optical waveguide device in afourth embodiment of the present invention. In this embodiment,description will be made to the arrangement of a circuit board includinga drive circuit driving the piezoelectric actuator and a method ofconnecting the piezoelectric actuator therewith. As shown in FIG. 7,lower substrate 6 a supporting the piezoelectric actuator is providedwith a insertion slot for securely supporting piezoelectric actuator 5a, and the base portion of the piezoelectric actuator is inserted intothe insertion slot. Furthermore, for electrical connection with acircuit board 25 arranged below, a wiring pin 17 is also inserted intothe insertion slot from the lower side through a pin hole 32. Wiring pin17 is electrically and mechanically connected with a connection terminal(not shown) of the piezoelectric actuator by solder 33.

[0069] The drive circuit for the piezoelectric actuator is formed bystacking a plurality of circuit boards 25. Since the piezoelectricactuator is normally driven at a high voltage such as 150V, it isdifficult to arrange the wiring pattern in high density. Then, two drivecircuits arranged to drive the adjacent piezoelectric actuators areallocated to the different circuit boards 25. Wiring pin 17 passesthrough pin hole 32 past the stacked circuit boards 25 and electricallyconnects to an electrode pattern 18 of the circuit board having thecorresponding drive circuit.

[0070] The optical waveguide device in accordance with the presentembodiment allows for the size reduction of the circuit board and thusthe optical waveguide device without causing a short circuit.

[0071] In the foregoing, although the embodiments of the presentinvention has been described, the embodiments of the present inventionas disclosed above are only illustrative and the scope of the presentinvention is not limited these embodiments of the invention. Forexample, the contact member may not be limited to the integrally formedmetal plate. Alternatively it may be formed with elastic resin.Furthermore, the drive member may not be limited to the piezoelectricactuator. The scope of the present invention is defined by descriptionin the claims and covers all equivalents and changes to the claims.

[0072] Although the present invention has been described and illustratedin detail, it is clearly understood that the same is by way ofillustration and example only and is not to be taken by way oflimitation, the spirit and scope of the present invention being limitedonly by the terms of the appended claims.

What is claimed is:
 1. An optical switch provided in an opticalwaveguide device including a waveguide allowing propagation of light anda waveguide accommodating sheet accommodating the waveguide, comprising:a cut portion formed by cutting in said waveguide accommodating sheetfrom one surface thereof across said waveguide; a contact member havinga fixed portion and a pressurizing portion at least on that side of saidwaveguide accommodating sheet which is opposite to a side of saidcutting in, said fixed portion being fixed in the vicinity of said cutportion, said pressurizing portion being positioned to be continuouswith the fixed portion and two-dimensionally overlap said cut portion;and a drive member positioned such that said pressurizing portion issandwiched between said drive member and said waveguide accommodatingsheet, whereby the drive member advances toward said pressurizingportion to press said pressurizing portion against said waveguideaccommodating sheet and retracts away from said pressurizing portion todisengage said pressurizing portion from said waveguide accommodatingsheet.
 2. The optical switch according to claim 1, wherein said contactmember and said drive member are provided on both face sides of saidwaveguide accommodating sheet, and one of two said drive members locatedon both face sides of said waveguide accommodating sheet presses onepressurizing portion against said waveguide accommodating sheet to openup said cut portion whereas the other drive member presses the otherpressurizing portion against said cut portion to connect said cutportion.
 3. The optical switch according to claim 1, wherein saidpressurizing potion includes a sheet contact portion to come intocontact with said waveguide accommodating sheet at said cut portion anda drive member contact portion to come into contact with said drivemember, and said sheet contact portion and said drive member contactportion are two-dimensionally separated.
 4. The optical switch accordingto claim 1, wherein said pressurizing portion includes a sheet-sideprotruding portion to come into contact with said waveguideaccommodating sheet at said cut portion and a drive member-sideprotruding portion to come into contact with said drive member.
 5. Theoptical switch according to claim 1, wherein said waveguideaccommodating sheet and said contact member have approximately the samethermal expansion coefficient.
 6. An optical waveguide device comprisingwaveguides allowing propagation of light, a waveguide accommodatingsheet accommodating said waveguides, and a plurality of optical switcheseach positioned at an intersection of said waveguides, each of saidoptical switches including a cut portion formed by cutting in saidwaveguide sheet from one surface thereof across said waveguide, acontact member having a fixed portion and a pressurizing portion atleast on that side of said waveguide accommodating sheet which isopposite to a side of said cutting in, said fixed portion being fixed inthe vicinity of said cut portion, said pressurizing portion beingpositioned to be continuous with said fixed portion andtwo-dimensionally overlap said cut portion, and a drive memberpositioned such that said pressurizing portion is sandwiched betweensaid drive member and said waveguide accommodating sheet, whereby thedrive member advances toward said pressurizing portion to press saidpressurizing portion against said waveguide accommodating sheet andretracts away from said pressurizing portion to disengage saidpressurizing portion from said waveguide accommodating sheet, whereinthe contact members positioned corresponding to each of a plurality ofsaid cut portions in said optical waveguide device are formed from onemetal plate that is integrally formed.
 7. The optical waveguide deviceaccording to claim 6, wherein said waveguide accommodating sheet isprovided with a frame portion along a peripheral portion of thewaveguide accommodating sheet, and said integrally formed metal plate isarranged to be surrounded with said frame portion.
 8. The opticalwaveguide device according to claim 6, further comprising a casingsupporting said waveguide accommodating sheet and said drive member,wherein said casing has approximately the same thermal expansioncoefficient as said drive member.
 9. An optical waveguide devicecomprising waveguides allowing propagation of light, a waveguideaccommodating sheet accommodating said waveguides, and a plurality ofoptical switches each positioned at an intersection of said waveguides,each of said optical switches including a cut portion formed by cuttingin said waveguide sheet from one surface thereof across said waveguide,a contact member having a fixed portion and a pressurizing portion atleast on that side of said waveguide accommodating sheet which isopposite to a side of said cutting in, said fixed portion being fixed inthe vicinity of said cut portion, said pressurizing portion beingpositioned to be continuous with said fixed portion andtwo-dimensionally overlap said cut portion, a drive member positionedsuch that said pressurizing portion is sandwiched between said drivemember and said waveguide accommodating sheet, whereby the drive memberadvances toward said pressurizing portion to press said pressurizingportion against said waveguide accommodating sheet and retracts awayfrom said pressurizing portion to disengage said pressurizing portionfrom said waveguide accommodating sheet, and an electrical drive unitelectrically driving said drive member, wherein said electrical driveunit is formed by stacking a plurality of circuit boards, and adjacentdrive members among said drive members are connected to differentcircuit boards.
 10. The optical waveguide device according to claim 9,further comprising a casing supporting said waveguide accommodatingsheet and said drive member, wherein said casing has approximately thesame thermal expansion coefficient as said drive member.